[Antitumor cross-resistance of trichinosis]. / Protivoopukholevaia krossreziztentnost' trikhinoza.

Our experiments were concerned with formation of antitumor cross-resistance by Trichinella spiralis infection in rats. Prophylactic infection was followed by an insignificant decrease in the number of 3,4-benzpyrene-induced malignant fibrous histiocytoma. It also inhibited mammary gland cancer induced by 7,12-dimethylbenzo(a)anthracene. No significant influence on the formation of fibroadenomas as a side effect was reported.

[The fatty acids of trichinellae]. / Zhirnye kisloty trikhinell.

The composition of fatty acids of lipids in the muscles of rats and larvae of Trichinella spiralis and T. nativa developing in them were studied. Both species are characterized by practically the same composition of fatty acids, only in the frost-resistant species T. nativa there was a sufficient amount (up to 3.5%) of docosapenta- and docosahexaenic acids (22:5 and 22:6). The comparison of the content of individual fatty acids in larvae and in muscles of the host by means of statistical correlation analysis suggests that larvae obtain a considerable portion of palmitic acid from the host and transform in into necessary long-chain saturated and unsaturated fatty acids by means of elongating and desaturating enzymes. Changes in the contents of fatty acids in larvae extracted from dead rats, which during some days were undergone freezing at negative temperatures (-8-10 degrees), are the same in quality for both species. These changes can be explained if we assume that the activity of elongases and desaturases of Trichinella decreases with cooling to a greater extent than the supply of palmitic acid from the host's tissues. A higher frost-resistance of T. nativa may be associated as with a greater protection of enzymes in the membranes by long-chain polyene acyls so with a higher thermal stability of proteins themselves.

[Method of crossbreeding Trichinella]. / O metodike skreshchivaniia trikhinell.

At the invasional larva stage all the species of Trichinella display different variations in the characters by which the sex can be identified. They should be taken into account in identifying trichinellids by crossing.

[Determination of the genetic kinship between nematode species of the genus Trichinella]. / Vyiavlenie geneticheskogo rodstva mezhdu vidami nematod roda Trichinella.

By crossing four Trichinella species the degree of their genetic relationship is detected. The closest relationship is determined between T. nelsoni and T. spiralis, and the remotest--between T. nativa and T. spiralis. Hybridization proceeds more successfully if Trichinella younger generation is used as a maternal organism than that in reciprocal combination.